Navigational technologies have evolved rapidly in recent years. For example, positioning systems such as the Global Positioning System (GPS) utilize satellite technology to enable people around the world to ascertain their current position and accurately navigate from one location to another. Other technologies are also used to determine an approximate location of a device user, such as mobile/cellular infrastructures that maintain a current location of communication devices carried by device users. These and other technological advances in navigation have in many cases supplanted printed maps, and have also enabled people to navigate between virtually any locations that would otherwise be unfamiliar to the navigator.
Location technologies (e.g. GPS, cellular, etc.) are in use in mobile devices. For example, automobiles may be equipped with GPS or other location devices to enable drivers to navigate along routes stored in accompanying software. Hand-held mobile devices may also be equipped with GPS or other location technologies, and in most cases inherently exhibit location abilities due to cellular/mobile infrastructure location tracking. Mobile device users can utilize navigation software facilitated by these location technologies. In the case of hand-held mobile devices, device users can take advantage of these navigation capabilities while on foot, while cycling, while driving an automobile, and so forth. For example, a user of a device equipped with such navigation capabilities can view a walking route, see his/her current location, and determine where he or she would like to travel.
The mobile devices in which such navigational capabilities are implemented are by nature limited devices compared to fixed and/or wired processing counterparts such as desktop computers. For example, a mobile phone is intended to be a small, convenient communication tool that can be carried by users, and notwithstanding the obvious benefits of such devices, mobile devices do not share the screen size, memory capabilities, or power considerations as fixed computing/communication devices. Power consumption is of particular interest in mobile device design, as battery size and discharge characteristics (e.g., processing intensity, talk time, standby time, etc.) impact the convenience and usefulness of such mobile devices.
In the case of mobile devices equipped with navigational devices, users often want to use the navigation system for relatively lengthy periods of time. A walker may want to use the navigation system for the entire day without changing or recharging the battery. Navigational features such as processor usage, display time and intensity, data communication (e.g. transceiver) time, etc. consumes power and can directly impact the available battery time. If the user uses the device and navigation system too long, the battery will lose power to the point that the device and/or navigation system can no longer be utilized until recharged.
Another issue with navigation systems is that they may provide visual and audio cues along the route. In many cases this is desirable, as the user welcomes the assistance provided by the navigation system. However, there may be times when the user is well aware of where he/she is located, and where he/she is going, and continual cues from the navigation system may be unnecessary and even annoying.
Accordingly, there is a need for manners of improving power efficiency of mobile devices employing navigation functionality. There is also a need to improve user usability of navigation features and feedback. The present invention fulfills these and other needs, and offers numerous advantages over the prior art.